for sitd_link and itd_link, put wmb after the last memory access to make sure ehci->period[frame] is visible by host before scheduling the descriptors Signed-off-by: pierre Kuo <vichy.kuo@xxxxxxxxx> --- drivers/usb/host/ehci-sched.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 980a6b3..11b517c 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -1754,8 +1754,9 @@ static void reserve_release_iso_bandwidth(struct ehci_hcd *ehci, itd->hw_next = *hw_p; prev->itd = itd; itd->frame = frame; - wmb(); *hw_p = cpu_to_hc32(ehci, itd->itd_dma | Q_TYPE_ITD); + /* make sure host see periodic frame change before scheduling */ + wmb(); } /* fit urb's itds into the selected schedule slot; activate as needed */ @@ -2157,8 +2158,9 @@ static int itd_submit(struct ehci_hcd *ehci, struct urb *urb, sitd->hw_next = ehci->periodic[frame]; ehci->pshadow[frame].sitd = sitd; sitd->frame = frame; - wmb(); ehci->periodic[frame] = cpu_to_hc32(ehci, sitd->sitd_dma | Q_TYPE_SITD); + /* make sure host see periodic frame change before scheduling */ + wmb(); } /* fit urb's sitds into the selected schedule slot; activate as needed */ -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
